454 FRUITS REPLACED BY OFFSHOOTS.offshoots. Similar in its behaviour is another Composite, the alpine AdenostylesCacalioe. It blossoms and fruits in sub-alpine forests even up to the tree hmit, butin high alpine regions, above 2200 metres in altitude, it never flowers, but formsoffshoots, and in this way fills httle depressions on alpine slopes with its vigorousfoliage. The terrestrial form of Polygonum amphibium occurs in a little bogclose to my country house in the Gschnitzthal in the Tyrol at a height of 1200metres. For twenty-eight years I have examined this bog every year without everfinding a ripe fruit upon these plants. But it propagates itself with rare luxurianceby means of offshoots and forms a broad girdle around the bog. These plants,Nardosmia frigida, Adenostyles Cacalioe, and Polygonum amphibium,, grown ina more favourable climate, produce good seed, but their vegetative methods ofpropagation are so restricted that one might almost suppose them to be differentspecies of plants. Instances in which flowers are replaced by offshoots or bulbils in the inflores¬cence may be mentioned in connection with the above. Polygonum vivi/parumand bulbiferum, Saxifraga cernua, nivalis, and stellaris, Juncus alpinus andsupinus, and the Grasses Aira alpina, Festuca alpina and ru/picaprina, Poaalpina and cenisia occur, it is true, with normally developed flowers and fruits,but in alpine, and especially in arctic regions, where these plants have their head¬quarters, one very frequently finds purely vegetative buds or bulbils, which becomedetached from the parent plant and give rise to new individuals, in place of flowersand fruit. In the Polygonums mentioned little bulbils replace a portion of theflowers. Saxifraga cernua usually produces a single terminal flower at the end ofits inflorescence, the lateral flowers being replaced by little tufts of bud-like offshootson short stalks (see fig. 342 ^). These buds, when they fall off, are either still closed(fig. 342 ^), or their thick, fleshy, outer scales are already parted, exposing a littlegreen foliage-leaf. On the ground they soon produce roots and grow into newplants (see figs. 342 ^ and 342''). In Saxifraga nivalis little shoots are formed inplace of flowers, each bearing a tuft-like rosette of minute leaves (flg. 342 '). Theserosettes are readily separable, and producing roots from their abbreviated axes,give rise to new plants. So also in the Juncuses and Grasses mentioned, httleshoots replace the fruits and come awajr from the inflorescence. These shoots areproduced in Poa alpina (see fig. 342 ^) and in most of the other Grasses mentioned,in the following manner. The axis of each spikelet, after producing several glumesat its base, forms green leaves above—as it were a grass-plant in miniature (see figs.342^ and 342^"). Later, these disarticulate, take root, and grow into new plants.More rarely do shoots arise laterally on the axis, in the axUs of subtending scales;when this is the case they faU away in the usual manner. The earlier Botaniststermed aU such Grasses, and indeed all plants which produce bulbUs in their inflor¬escences, viviparous, the idea being, that in all of them the seeds germinatedprecociously whilst stiU attached to the parent. This view was probably suggestedby the common experience of agriculturalists that Rye, Oats, and other cerealssometimes " sprout", i.e. that when the spikes are continually wetted by rain about